Module metrics
Source - CounterMetrics
 CounterMetrics is used in two contexts within the metrics system:- MetricKey
 - Unique key for a metric: name + labels
 - MetricsReport
 - Data structure containing the actual metrics for a transaction,
organized into different categories
 - TimingMetrics
 - Time-related metrics for performance analysis of transaction execution phases
 - TransactionInfo
 - Transaction-level information that persists across retries
 - TransactionMetrics
 - Tracks metrics for a transaction.
 
- FdbCommand
 - Represents a FoundationDB command.
 
- Labels
 - Label key-value pairs for metrics